Release of deposited MnO2 nanoparticles from aqueous surfaces  

作　　者：Hainan Wang Ruixing Huang Chengxue Ma Xiaoling Li Caihong Liu Qiang He Zhengsong Wu Jun Ma Xiaoliu Huangfu 

机构地区：[1]Key Laboratory of Eco-environments in Three Gorges Reservoir Region,Ministry of Education,College of Environment and Ecology,Chongqing University,Chongqing 400044,China [2]Key Laboratory of Water Supply and Sewage Engineering,Ministry of Housing and Urban-Rural Development,School of Civil Engineering,Chang’an University,Xi'an 710054,China [3]State Key Laboratory of Urban Water Resource and Environment,School of Municipal and Environmental Engineering,Harbin Institute of Technology,Harbin 150001,China

出　　处：《Journal of Environmental Sciences》2020年第4期234-243,共10页环境科学学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.51878092,51608067);the Scientific and Technological Innovation Special Program of Social Livelihood of Chongqing(No.cstc2015shmsztzx0053);the Fundamental Research Funds for the Central Universities(No.2019CDXYCH0026)

摘　　要：Changes in solution chemistry and transport conditions can lead to the release of deposited MnO2 nanoparticles from a solid interface,allowing them to re-enter the aqueous environment.Understanding the release behavior of Mn02 nanoparticles from naturally occurring surfaces is critical for better prediction of the transport potential and environmental fate of Mn02 nanoparticles.In this study,the release of Mn02 nanoparticles was investigated using a quartz crystal microbalance with dissipation monitoring(QCM-D),and different environmental surface types,solution pH values and representative macromolecular organics were considered.Mn02 nanoparticles were first deposited on crystal sensors at elevated NaN03 concentrations before being rinsed with double-deionized water to induce their remobilization.The results reveal that the release rate of Mn02 depends on the surface type,in the decreasing order:SiO2>Fe304>Al2 O3,resulting from electrostatic interactions between the surface and particles.Moreover,differences in solution pH can lead to variance in the release behavior of Mn02 nanoparticles.The release rate from surfaces was significantly higher at pH 9.8 that at 4.5,indicating that alkaline conditions were more favorable for the mobilization of Mn02 in the aquatic environment.In the presence of macromolecular organics,bovine serum albumin(BSA)can inhibit the release of Mn02 from the surfaces due to attractive forces.In presence of humic acid(HA)and sodium alginate(SA),the Mn02 nanoparticles were more likely to be mobile,which may be associated with a large repulsive barrier imparted by steric effects.

关 键 词：QCM-D Release kinetics MnO2 nanoparticles(MnO2 NPs) Solution pH BIOMACROMOLECULE 

分 类 号：X52[环境科学与工程—环境工程]